Presser-foot-locking device for sewing-machines



E. ERICKSON.

PRESSER FOOT LOCKING DEVICE FOR SEWING MACHINES.

APPLICATION FILED APR.24. 1915.

ii E. 9%,%@ 1 Patented Aug. 15, 1916.

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E. ERICKSON.

PRESSER FOOT LOCKING DEVICE FOR SEWING MACHINES.

APPLICATION FILED APR.24.19I5.

1,19%,491. PatentedAug. 15,1916.

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MACHINERY COMPANY, OF BOSTON, MASSACHUSETTS,

MASSACHUSETTS.

A CORPORATION OF PBESSER-FOOT-LOCKING DEVICE FOR SEWING-MACHINES.

wearer.

Continuation in part of application Serial No. 739,056, filed December 28, 1912.

Specification of Letters Patent.

Patented Aug. 15, 1916.

This application filed April 24, 1915. Serial No. 24,138.

Machines, of which the following is a specifi-' cation.

Thls invention relates to machines for sewing heavy material, such as leather, and

refers particularly to that type of such 1nachines known as welt sewlng machines, and has for its 0b]ect the provlsion of means whereby the presser foot may be locked during the stitch forming operation and may be unlocked autom atlcally only durlng the work feeding operation and by the operator only when the awl and needle are removed from the work.

The present invention is an improvement on another invention shown and described in another patent of mine dated April 27,1915,

and numbered 1,137,193, to which reference may be made for the operation of the sewing machine as a whole.

The invention consists in certain novel features of construction and arrangement of parts which will be fully understood by reference to the description ofthe drawings and to the claims hereinafter given.

Of the drawings: Figure 1 represents a vertical section of a sewing machine embodying the principles of the present invention. Fig. 2 represents a vertical section of the presser foot actuating mechanism, and Fig. 3 represents a vertical section of the same drawn to an enlarged scale, the cutting plane being on line 3-3 on Fig. 2.

Similar characters designate like parts throughout the several figures of the drawings. I I

In the drawings, 30 is the base of themachine and is provided with the usual uprights or standards 31, in which is mounted the main shaft. 34 adapted to be rotated by the driving pulley 38. The machine is pro vided with the usual awl 174 for puncturing the work and the usual oscillating curved needle 151, these being driven in the manner described in the application hereinbefore referred to or in any other well-known manner. The machine is also provided with a shuttle and the other instrumentalities necessary for forming a stitch, but as these devices form no part of the present invention they are neither shown nor described herein, 1t being possible to refer to'the application above referred to for one form of stitch forming mechanism which may be used in connection withthe present invention.

The work support 71, provided with the usual slot to permit the feeding motion of the awl 174:, may be secured to the frame of the machine in any well-known manner.

The arm 74 having the presser foot 75 (Fig. 1) is secured, by means of suitable screws or bolts, in a recess 7 6 of an arm 77 ofa lever, the other arm 7 8 of which is formed or provided with a segment rack 79 meshing with a pinion 80. The lever 77, 78 is pivotally supported on the member 78*. The pinion 80 has a sleeve hub 82 mounted loosely upon a pin or stud shaft 83 eccentrically carried by a disk 84- (Figs. 2 and 3) said disk being carried by a stud shaft 85 mounted in an arm 86 of a standard 31.

A split ring 87 is clamped upon the disk 84, as by means of a binding screw or bolt 88, said ring 87 having an arm 89 provided with aroll 90 engaging a cam groove 91 in one side of a cam disk 92 carried by the shaft 34, whereby prior to the feeding of the work, the pin 83 on which the pinion 80 is mounted is oscillated relatively to the axis of the stud shaft 85 and lifts the presser foot from contact with the work and permits'thevlatter to be fed. After the work has been fed the pin 83 is returned to its normal position, thus moving the presser foot into gripping contact with the work. The split ring 87 enables an adjustment to be effected between the arm 89 and the disk 84.

To cause the presser foot to bear with yielding pressure upon the work, I employ a spring 93 (Fig. 3), one end of said spring being connected to the pinion 80 and the other end connected to a collar 94:, the latter having a series of radial notches 95 in its outer end, with either one of which a pin 96 projecting from the pin 83 is adapted to be engaged. The pin and notch construction just described is for the purpose of enabling the tension of the spring 93 to be adjusted so as to force said spring to act through the to hold the Work tightly during the formation of each stitch, and to release it during the feed of the Work, I provide the following mechanism: Mounted upon the sleeve hub 82 of the cam 80 are the two recessed hubsor collars 97, 98, a spring 99 being located in the recess and adapted, as presently explained, to act as a brake upon the outer periphery of the sleeve hub 82. One end of said spring is connected to the hub 98 and the other to the hub 97. The latter has an arm 100 provided with a pin 101 which enters a slot in an adjustably fixed arm 102 pivotally connected at 103'to a standard 31 (Fig. The lower end of the arm 102 is formed with an arc slot 101 (Fig. 2) through which a binding screw 105 passes into the standard. This provides for so adjustably securing thearm 102 as to vary the position of the hub 97 rotatably to slightly loosen or tighten the brake spring 99 as may be necessary to insure the accurate operation of said spring as a brake. The hub 98 has an arm 106 (Fig. 2) which is connected by a link 107 to one arm 108 of an elbow lever pivoted at 109, the other arm 110 having a roll 110 which engages a cam groove 111 in the side of the cam disk 92.

The pivot 109 is a pin which extends through a standard 31 and projects at each end from said standard, being mounted to oscillate in a hole in said standard. At one end this pin 109, which is practically a rockshaft, has a pinion 112 (Fig. 1) meshing with a rack 113 carried by a vertically movable rod 114, which may be connected to a treadle not shown to raise the presser foot when work is to be introduced. The other 7 end of the rockshaft 109 is provided with a cam-shaped projection 116 (Fig. 2) which enters an opening or slot in one end of a pivoted arm 117, said arm being pivotally connected at 118 to the arm 110 of the elbow lever. The arm 117 has a roll 119 which bears against the periphery of the cam disk 92, the latter having a recess or depression 120. As will be readily understood, when the parts occupy the relative positions shown in Figs. 1 and 2, the arm 117 forms practically a rigid portion of the arm 110 of the elbow lever, the rolls carried by these two arms engaging opposite sides of the rib of the cam disk92 which separates the cam groove 111- from the periphery of the cam,

and therefore as the cam diskrotates the elbow lever is oscillated, the structure and operation of the parts being such that when the operative portion of the cam groove 111 reaches the roll 110 on the arm 110 the elbow lever is oscillated to tighten the brake spring 99 (Fig.3), this occurring during the formation of each stitch. As will be explained hereinafter, the operation of the foot treadle rod 114: acts to oscillate the rock shaft 109 to rotate the cam projection 116 sufficiently to allow relative movement of the arms 110, 117 at a predetermined point in the cycle of the cam disk 92. As best shown in Fig. 1, the inner wall of the cam groove 111 is provided with a recess 121 which, when it arrives opposite the roll 110 of the arm 110, will permit said roll to more toward the axis of rotation of the cam disk 92 so as to relieve outward pressure on said roll and thus release the braking effect of the brake spring 99 and permit the presser foot to be lifted. The roll 119 of the lever 117 is normally held in engagement with the periphery of the cam 92 by means of the cam 116 coacting with the slot in said lever 117 (see Fig. 2). A projection 200 on a fixed part of the frame 31 is provided to limit the outward movement of the said lever 11.7 and acts as a fulcrum for said lever when thecam 116 is revolved at a predetermined time to release the brake and presser foot mechanism preparatory to removing work from the machine or placing work therein. It is obvious, therefore, that when the cam projection 116 is moved about the axis of the rock shaft 109 it will tend to separate the rolls 119 and 110*, but as the roll 110 is in a cam path 111 and the roll 119 is prevented from moving outwardly, such separation is prevented until the depression 121 is opposite the roll 110 when such separation may occur. This separating movement of the rolls 110* and 119 will more the pivot 118 toward the axis of the shaft 31 and thereby raise the outer end of the arm 108 and thus through the link 107 effect the release of the binding of the spring 99 upon the sleeve 82 and unlock the presser foot controlling member 80. This release is effected through the upward movement of the member 114, the rack 113 thereon first oscillating the pinion 112 to release the locking device. Subsequently the end of the member 11 1 in its upward movement comes into contact with the outer end of a lever 228 pivoted at 229 to a part of the frame and moves it about said pivot so that its opposite end engaging the shoulder 227 on the presser foot carrier 78 will move said carrier about its pivot 78 and lift the presser foot 75 from the work. It is self-evident, therefore, that the locking device retains the presser foot in fixed position in gripping contact with the work during the stitch forming operation and that the locking device is released automatically in each cycle of the cam disk 92 by the cam throw 120, this unlocking being timed to occur when the work is about to be fed. At all other times the presser foot is locked and cannot be unlocked except by the operator, and then only at a single point in the cycle of the cam disk 92, that is, when the depression 121 is opposite the roll 110*. At this time only can the cam projection 116 operate to effect the release ofv the locking device and will operate then only when positively actuated by the operator.

The depression 121 is so positioned on the cam disk 92 and so timed relatively to the operation of the instrumentalities effecting the formation of the stitch that the release of the locking means by devices under control of the operator may only occur when the needle and awl are out of the work and the awl is ready to move upwardly into the work. It is obvious, therefore, that when new work is placed upon the work support 71 the next operation of the machine will always be the piercing of the work by the awl 174E. Ihis locking of the presser foot on the work so that the work cannot be removed until the completion of a stitch is obviously of great advantage.

When the spring 99 is operated to lock r the presser foot controlling member the first action thereof as it tightens on the controlling member shaft 83 will be to move the presser foot toward the work and into contact therewith, and the final action thereof will be to firmly grip said controlling member shaft and lock the presser foot on the work so that any lifting of the work is effectually prevented. Obviously the coiling of this spring on the member 88 to effect a locking of the presser foot controllingmember will first by its frictional contact with the periphery of the member 83 create a yielding pressure on the presser foot.

It is believed that the operation and many advantages of this invention will be fully understood from the foregoing description.

Having thus described my invention, I claim:

1. In a sewing machine, the combination of a presser foot; a pivoted carrier therefor having a lateral projection, a pivoted lever one arm of which is in engagement with said projection; mechanism for locking said presser foot during the stitch forming operation including in part an oscillating pinion; a rack engaging said pinion and under the control of the operator adapted to be moved to release said locking means and subsequently engage the outer end of the lever in engagement with said projection and move it about its pivot thereby causing said carrier to be moved about its pivot.

2. In a sewing machine, the combination of an oscillating presser foot controlling member; a locking spring coiled about said member and adapted to bind thereon to prevent oscillation. thereof; a revoluble disk with a cam path therein, a revoluble shaft; a bell crank lever pivotally mounted thereon and having a roll on one arm in said cam path; means connected to the other arm adapted to control the locking action of said spring; a lever pivoted to one arm of said bell crank lever having at one end a roll engaging the periphery of said cam disk and provided with a slot at its opposite end; a cam projection on said shaft positioned in said slot; a stop member to limit the movement of said slotted lever about its pivot; means for rotating said shaft; and means for automatically releasing said locking spring from said controlling member prior to the feeding of the work.

3. In a sewing machine, the combination of an oscillating presser foot controlling member; a locking spring coiled about said member and adapted to bind thereon to prevent oscillation thereof; a revoluble disk with a cam path therein; a pivoted member having a roll in said cam path; means secured to said member for controlling the locking action of said spring; and a lever pivoted to said member with a roll at one end and having provision for retaining said roll in engagement with the periphery of said disk.

1. In a sewing machine, the combination of an oscillating presser foot controlling member; a locking spring coiled about said member and adapted to bind thereon to prevent oscillation thereof; a revoluble disk with a cam path therein; a pivoted member having a roll in said cam path; means secured to said member for controlling the locking action of said spring; a lever pivoted to said member with a roll at one end and having provision for retaining said roll in engagement with the periphery of said disk; and means for separating said rolls to permit the unlocking of said spring operative at one point only in the revolution of said disk.

5. In a sewing machine, the combination of an oscillating presser foot controlling member; a locking spring coiled about said member and adapted to bind thereon to prevent oscillation thereof; a revoluble disk with a cam path therein; a pivoted member having a roll in said cam path; means secured to said member for controlling the locking action of said spring; a lever pivoted to said member with a roll at the outer end thereof; means to limit the outward movement of said lever; and means coacting with said lever for normally retaining its roll in engagement with the periphery of said disk, and adapted to rock said lever about said limiting means thereby separating said rolls and effecting the release of said locking spring at a predetermined time.

6. In a sewing machine, the combination of a presser foot; a pivoted carrier therefor; a revoluble member controlling the operation of said presser foot; mechanism another collar surrounding for oscillating said carrier about its pivot including a helical spring coiled about said revoluble presser foot controlling member whereby the presser foot is locked during having a gear segment formed thereon; a-

pinion meshing therewith provided with a tubular hub; an oscillating disk; a support for said pinion eccentrieally mounted on said oscillating disk; a revoluble disk having cam paths on opposite faces one for moving said carrier about its pivot and the other for controlling the presser foot locking means; an arm extending from said oscillating disk and provided with a roll in one cam path; a spring coiled around said sleeve; a collar on. said sleeve to which one end of said spring is secured; another collar surrounding said coiled spring to which the other end of said spring is secured, saidcollar having a pro ecting arm; a link pivotally connected at one end to said arm; an oscillating shaft; a bell crank lever pivotally mounted thereon, one arm of which is connected to said link while the other arm is provided with a'roll engaging the other cam path of said cam disk, said cam path having a depression in its inner Wall; a lever pivoted to said bell crank lever and having at one end a roll engaging the periphery of said cam disk and a slot in its opposite end;

a stop member to limit the outward movement of the roll end of said lever; a cam member on said oscillating shaft and positioned in said slot;.and means for oscillating said cam member.

' 8. In a sewing machine,'the combination of a presser foot; a pivoted carrier therefor having a gear segment formed thereon; a pinion meshing therewith provided with a tubular hub; a support therefor eccentrically mounted on an oscillating disk; a revoluble disk having cam paths on opposite faces, one for moving said carrier about its pivot and the other for controlling the presser foot locking means; an arm extending from said oscillating disk and provided with a roll in one cam path; a spring coiled around said sleeve; a collar on said sleeve to which one end of said spring is secured; said coiled spring to which the other end of said spring is secured, said collar having a projecting arm; a link pivotally connected at one end Copies of this patent may be obtained for five cents each, by addressing the to said arm; an oscillating shaft; a bell crank lever pivotally mounted thereon, one arm of which is connected to said link while the other arm is provided with a roll engaging the other cam path of said cam disk, said cam path having a depression in its inner wall; a lever pivoted to said bell crank lever and having at one end a roll engaging the periphery of said cam disk and a slot in its opposite end; a stop member to limit the outward movement of the roll end of said lever; a cam member on said oscillating shaft and positioned in said slot; means for oscillating said cam member; and means for locking the first mentioned collar in adjusted position to regulate the tension of the locking spring.

9. In a'sewing machine, the combination of a presser foot; a pivoted carrier therefor having a gear segment formed thereon; a pinion meshing therewith provided with a tubular hub; a support therefor eccentrically mounted on an oscillating disk; a revoluble disk having cam paths on opposite faces one for moving said carrier about its pivot and the other for controlling the presser foot locking means; an arm extending from said oscillating disk and provided with a roll in one cam path; a spring coiled around said sleeve; a collar on said sleeve to which one end of said spring is secured; another collar surrounding said coiled spring to which the other end of said spring is secured, said collar having a projecting arm; a link pivotally connected at one end to said arm; an oscillating shaft; a bell crank lever pivotally mounted thereon, one arm of which is connected to said link while the other arm is provided with a roll engaging the other cam path of said cam disk, said cam path having a depression in its inner wall; a lever pivoted to said bell crank lever and having at one end a roll engaging the periphery of said cam disk and a slot in its opposite end; a stop member to limit the outward movement of the roll end of said lever; a cam member on said oscillating shaft and positioned in said slot; means for oscillating said cam member; a pivoted actuator adapted to engage the presser foot carrier and move it about its pivot; a pinion on said oscillating shaft; and a movable member having a rack engaging said pinion and adapted in its movement to oscillate saidactuator about its pivot and effect the lifting of the presser foot.

Signed by me at 4 P. 0. Sq., Boston, Mass. this 22nd day of April, 1915.

EDWARD. ERICKSON.

Commissioner of Patents.

Washington, .D. G. 

